Thirty-six relatives of ‘missing persons’ were arrested by police from outside President Arif Alvi's residence in Karachi's Mohammed Ali Society on Wednesday following the lodging of a first information report (FIR) against the organisers of the sit-in on behalf of the state.

The relatives had been protesting for the recovery of their 'missing' loved ones since April 28 outside the president's house, located on Fatima Jinnah Road in the limits of Bahadurabad police station.

The police registered an FIR against five nominated persons as well as 250-300 unknown persons over a host of charges ranging from riots to waging war against the country.

The law enforcement agencies launched a crackdown against the participants of the sit-in today and apprehended some three dozen protesters, including Hasan Raza, one of the organisers, said Rashid Rizvi, the head of the Missing Persons’ Relatives Committee.

Rizvi vowed that they would "not be deterred by such high-handed tactics of the law enforcers and would continue [their] protest till the recovery of victims of enforced disappearances".

A senior police officer who wished not to be named told Dawn that the police did not use any force against the protesters. However, the officer admitted that several persons were detained as they were nominated in the FIR. The officer said that some of them could be released following an inquiry.

The police have invoked several sections of the Pakistan Penal Code (PPC) against the protesters, including 147 (punishment for rioting), 148 (rioting, armed with deadly weapon), 120-B (punishment of criminal conspiracy), 121 (waging or attempting to wage war or abetting the waging of war against Pakistan), 121-A (conspiracy to commit offences punishable by Section 121), 341 (punishment for wrongful restraint), 427 (mischief) and 503 (criminal intimidation).